Digital Video Forums  

Go Back   Digital Video Forums > Video File Formats > AVI, DivX/Xvid

Reply
 
LinkBack Thread Tools Search this Thread Rate Thread Display Modes
Old 16 Apr 2003, 03:09 PM   #1
Junior Member
Junior Member
 
Join Date: Feb 2003
Posts: 11
Default Re-encoding DivX file to make it smaller???

Hi,
Can a DivX file be (somehow) re-encoded into DivX format in order to change the resulting file size?
I have a DivX movie file but it's too big for a single CD. Can it somehow be re-compressed into a smaller file size?
Thanks.
mazdivx is offline   Reply With Quote
Old 16 Apr 2003, 07:35 PM   #2
Digital Video Technician
Digital Video Technician
 
Join Date: Nov 2001
Posts: 462
Default

To get the best results,do a two-pass encoding.

If DivX 3.11 is preferred :

1. Open file in NanDub
2. Set Video tab to Fast Recompress
3. Set Audio tab To Diresct Stream Copy
4. Video-->SBC Options-->SBC Settings
5. Set up the codec with the proper bitrate.
6. File-->Two passes
7. Give the .avi and .stats a name.

For DivX 4-->

1. Open file in VirtualDub
2. Set Video tab to Fast Recompress
3. Set Audio tab To Diresct Stream Copy
4. Video-->Compression
5. Select the proper codec
6. Select 2-pass,first pass
7. Choose a dir. for the log file.
8. Save .avi (wait until finished)
9. Video-->Compression
10. Select 2-pass,second pass and input the right bitrate.
11. Save .avi

Last edited by gs0666; 16 Apr 2003 at 07:41 PM
gs0666 is offline   Reply With Quote
Old 16 Apr 2003, 08:54 PM   #3
Super Moderator
 
UncasMS's Avatar
 
Join Date: Nov 2001
Posts: 9,047
Default

depending on the present file size i would rather re-encode the audio stream to something smaller and cut off end-credits.

all else will decrease the quality too much.

a 100min movie with 128kbps mp3 takes some ~91.5 mb for the audio stream

same movie with ogg vorbis instead of mp3 and a bitrate of 74kbps will only need ~52.9mb

this way you could easily get rid of some 30-40mb.

cutting off end credits will give you even more reduction of your final file size.
__________________
UncasMS is offline   Reply With Quote
Old 17 Apr 2003, 05:55 AM   #4
Junior Member
Junior Member
 
Join Date: Feb 2003
Posts: 11
Default

In order to use Ogg Vorbis for the audio, wouldn't I first need to demultiplex the audio and video? If so, how do you do that?
Also, how can I determine what exact bitrate to use when re-encoding the audio and video? Can a regular bitrate calculator be used for a video file which is already in DivX form?
Thanks.
mazdivx is offline   Reply With Quote
Old 17 Apr 2003, 06:04 AM   #5
Junior Member
Junior Member
 
Join Date: Feb 2003
Posts: 11
Default

...and another question.
gs0666 gave options to recompress using DivX 3.11 or 4. Why doesn't DivX5.0x show up in the VirtualDub compression list as one of the options (I know I have it installed)?
Thanks.
mazdivx is offline   Reply With Quote
Old 17 Apr 2003, 06:57 AM   #6
Super Moderator
 
UncasMS's Avatar
 
Join Date: Nov 2001
Posts: 9,047
Default

demuxing:

- load avi in virtualdubMOD
- avi => demux audio
this will save your audio stream(s)

to save tha video stream only set audio 1/2 to NONE and video to direct stream. then use avi => save as avi

now you should have two separate file with exact sizes on which to base your calculations.

to calculate how big an audio file will be take a look at this example:

100 (minute movie) x 60 (seconds) x e.g. 128000 (i.e. 128kbps) / 8 / 1024 /1024 =>

6000 x 128000 / 8/1024▓ => 91.55mb
UncasMS is offline   Reply With Quote
Old 17 Apr 2003, 05:11 PM   #7
Junior Member
Junior Member
 
Join Date: Feb 2003
Posts: 11
Default

OK,
I have successfully demuxed the file into two separate files: audio (.mp3) and video (.avi DivX).
Now could you please tell me how to re-encode the demuxed .mp3 audio file into Ogg Vorbis format?

I plan to use an audio bitrate determined as follows:

audio bitrate in bps =
{(8)(1024^2)[700 - (video filesize in MBytes)]} / (60)(movie length in minutes)


Thank you.
mazdivx is offline   Reply With Quote
Old 18 Apr 2003, 05:01 AM   #8
Super Moderator
 
UncasMS's Avatar
 
Join Date: Nov 2001
Posts: 9,047
Default

here is an ogg vorbis guide:

http://www.atlandide.net/~uncasms/images/ogg/ogg_e.htm

how big is your current audio file btw?
UncasMS is offline   Reply With Quote
Old 18 Apr 2003, 05:41 AM   #9
Junior Member
Junior Member
 
Join Date: Feb 2003
Posts: 11
Default

My current .mp3 audio file is about 82MB.

I read your OGG/OGM guide and followed the directions. Everything worked out very well and I got a smaller .ogg file which I multiplexed with the video file using VirtualDubMOD and got a final .ogm movie file. The final movie size will easily fit on CD.

The thing I didn't understand is after the .mp3-to-.ogg transcoding was completed, a text message said the birate used was around 77kbps. But then I checked the OGG Quality factor and it was 90kbps (0.200) and the .ogg file size was smaller than what I expected. I had forgotten to set it before starting the transcoding.
But anyway, everything worked out great in the end.

Thank you very much for your help.
mazdivx is offline   Reply With Quote
Old 18 Apr 2003, 06:01 AM   #10
Super Moderator
 
UncasMS's Avatar
 
Join Date: Nov 2001
Posts: 9,047
Default

i'm glad everything finally worked out for you

an alternaty could be burning the oversized file as mode2cd

search the net and you'll find the filter as well as some hints on mopde2cd / xcd
UncasMS is offline   Reply With Quote
Reply

Bookmarks


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off




All times are GMT +10. The time now is 11:29 PM.

Kirsch designed by Andrew & Austin


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
Copyright © 1999 - 2018 Digital Digest

Visit DivXLand   Visit dvdloc8.com